This application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2007-197655 filed in Japan on Jul. 30, 2007, the entire contents of which are hereby incorporated by reference.
The present invention relates to original transport and reading apparatuses provided with an image reading unit in which the reading position for reading an image of an original is changed, reading position adjustment methods of original transport and reading apparatuses in which reading positions are adjusted, and image forming apparatuses provided with original transport and reading apparatuses that are provided with an image reading unit in which the reading position is changed.
Original transport and reading apparatuses have been proposed that are provided with an original transport apparatus having a transport path on which an original is transported, a first image reading unit that is arranged in opposition to the original transport apparatus and reads an image of a transported original at a first reading position that is demarcated along the transport path, and a second image reading unit that is arranged on an inner side of a casing of the original transport apparatus and reads an image of a transported original at a second reading position that is demarcated along the transport path.
This second image reading unit of the original transport and reading apparatus is arranged on an inner side of the casing of the original transport apparatus and reads an image of originals at a fixed second reading position, and therefore there is a problem in that maintenance of the reading light path cannot be executed easily.
That is, maintenance (cleaning) of the reading light path is executed by disassembling the inside of the original transport apparatus and withdrawing the second image reading unit.
Accordingly, an obstruction (for example, smearing or the like adhering to the reading glass) that occurs when reading an original with the reading light path of the second image reading unit cannot be removed easily, thereby causing a flaw (a white streak or a black streak or the like) in the image that is formed, which produces a problem in terms of image quality.
It should be noted as prior art that image reading apparatuses have been disclosed in which the reading position is changed by revolving a turning mirror (for example, see JP H01-277054A).
The present invention has been devised in consideration of these issues, and it is an object thereof to provide an original transport and reading apparatus provided with an original transport apparatus having a transport path on which an original is transported, in which by changing an arrangement of a reading light path formed by the image reading unit by changing a reading position that is demarcated along the transport path, an obstruction that has occurred on the reading light path is avoided to read an image of the original.
Furthermore, another object of the present invention is to provide a reading position adjustment method of an original transport and reading apparatus that adjusts a reading position of an original transport and reading apparatus provided with an original transport apparatus having a transport path on which an original is transported, wherein by comparing a pixel output value against a reference value for each pixel of an image sensor of the image reading unit to detect an abnormal state in advance and by changing the reading position until the abnormal state is eliminated, it is possible to obtain image data with high precision avoiding obstructions on the reading light path and to prevent in advance an occurrence of a problem in the image to be formed.
Furthermore, another object of the present invention is to achieve an image forming apparatus that is provided with an original transport and reading apparatus that transports an original and reads an image of the original, and an image forming unit that forms an image based on image data read by the original transport and reading apparatus, wherein by changing an arrangement of the reading light path formed by the image reading unit of the original transport and reading apparatus, an image of the original is read with high precision avoiding obstructions produced on the reading light path so that no flaws (white streaks, black streaks or the like) are produced in the image to be formed.